SAN DIEGO — Homeland Security buses carrying migrant children and families were rerouted Tuesday to a facility in San Diego after American flag-waving protesters blocked the group from reaching a suburban processing center.

The standoff in Murrieta came after Mayor Alan Long urged residents to complain to elected officials about the plan to transfer the Central American migrants to California to ease overcrowding of facilities along the Texas-Mexico border.

Many of the immigrants were detained while fleeing violence and extortion from gangs in Guatemala, El Salvador and Honduras.

After the buses were blocked, federal authorities rerouted the vehicles to a freeway and then to a customs and border facility in San Diego within view of the Mexico border.

The three buses were trailed by a half-dozen news crews during the two-hour trip. People near the San Diego facility were surprised by the caravan.

Juan Silva, 27, a welder in Chula Vista, said he thought officials were transporting drug traffickers. Then he heard the buses were carrying migrant families.

“I don’t think people in that town should be against little kids,” he said about the protesters in Murrieta. “We’re not talking about rapists, we’re talking about human beings. How would they feel if it was their kids?”

After the migrants are processed, Immigration and Customs Enforcement will decide who can be released while awaiting deportation proceedings.

Earlier in the day, a chartered plane landed in San Diego with 136 migrants on board, according to a Department of Homeland Security official who was not authorized to be named when speaking on the issue.

It was the first flight planned for California under the federal government’s effort to ease the crunch in the Rio Grande Valley and deal with the flood of Central American children and families fleeing to the United States.

The government is also planning to fly migrants to Texas cities and another site in California, and has already taken some migrants to Arizona.

More than 52,000 unaccompanied children have been detained after crossing the Texas-Mexico border since October in what President Barack Obama has called a humanitarian crisis. Many of the migrants are under the impression that they will receive leniency from U.S. authorities.

Another flight was expected to take 140 migrants to a facility in El Centro, California, on Wednesday, said Lombardo Amaya, president of the El Centro chapter of the Border Patrol union. The Border Patrol would not confirm that arrival date.